1. Field of the Invention
The present invention relates to a processing apparatus and, more particularly, to a processing apparatus including a processing unit which processes an object.
2. Description of the Related Art
An exposure apparatus to manufacture a device such as a semiconductor device is usually used by connecting it to a coating and developing apparatus. A wafer coated with a photosensitive agent is transferred between the exposure apparatus and coating and developing apparatus. An inlet/outlet station is inserted between the exposure apparatus and coating and developing apparatus. The exposure apparatus removes a wafer placed on the inlet/outlet station, and requests the coating and developing apparatus to supply the next wafer at the timing when the exposure apparatus becomes capable of receiving the next wafer.
When transferring an exposed wafer to the coating and developing apparatus, the exposure apparatus places the wafer on the inlet/outlet station and requests the coating and developing apparatus to remove it from the inlet/outlet station at the timing when the coating and developing apparatus becomes capable of receiving the wafer.
According to the above scheme of requesting the coating and developing apparatus to supply the next wafer at the timing when the exposure apparatus becomes capable of receiving the next wafer, the coating and developing apparatus operates a conveyer upon reception of this request. Assume that the time necessary for the coating and developing apparatus to actually place the wafer on the inlet/outlet station after it receives a wafer supplying request is a time T. The exposure apparatus cannot receive the next wafer until the time T elapses since the timing when it can receive the next wafer.
According to the above scheme of requesting the coating and developing apparatus to remove the wafer from the inlet/outlet station at the timing when the coating and developing apparatus becomes capable of receiving the wafer, the coating and developing apparatus operates the conveyer upon reception of this request. Assume that the time necessary for the coating and developing apparatus to remove the wafer from the inlet/outlet station after it receives a wafer removing request is a time T. The exposure apparatus cannot place the next wafer on the inlet/outlet station until the time T elapses since the timing when the coating and developing apparatus becomes capable of receiving the wafer.